When must an operator test a cargo tank motor vehicle equipped with an off-truck remote shutoff system?

The requirement for testing a cargo tank motor vehicle equipped with an off-truck remote shutoff system is specifically designed to ensure that the safety features of the system are operational before any transfer of liquefied petroleum gas (LPG) occurs each day. Conducting the test 18 hours prior to the first delivery allows enough time for any necessary adjustments or repairs to be made if the system fails the test, thereby ensuring safety during the transportation and delivery processes.

This particular timing is critical for compliance with safety regulations, as it adds a layer of precaution that can prevent accidents or leaks during the delivery of LPG. Regular testing guarantees that the equipment operates correctly under potential emergency conditions, ensuring that the shutoff mechanism can be activated remotely if needed, which is essential to minimize risks associated with the handling of liquefied petroleum gases.

With regard to the other options, testing prior to repairs, after every delivery, or weekly does not align with the specific safety protocols set forth in the NFPA guidance. The outlined timeframe of 18 hours before the first daily delivery addresses the specific operational rhythm of cargo tank vehicles, ensuring that readiness is confirmed ahead of each day's service.